A difficulty arises when attempts are made to temporarily cover an opening. By way of example only and not by limitation, windows, glass doors and the like are provided in homes and offices to allow light in and a view out. However, on occasion it is useful or necessary to cover the opening and sometimes it is required to fully “black out” the opening. As used herein, the term “black out” is used to describe a condition where an opening is covered sufficiently to allow essentially no or very little light to pass. Then, again, there are situations where some light is desired but the view in or out is required to be obscured. Then also, there are times when full visibility is desired and no covering is wanted.
Further, it is important for an opening covering system to be as quiet as possible and as compact as possible. The system should not be overly complex to install and maintain and it should be easily adaptable to openings with different dimensions.
A wide variety of devices have been developed in attempts to address at least some of these requirements. Sloop et al., U.S. Pat. No. 4,766,941, discloses an electrically powered oppositely positioned pair of rollers, one at the top of the window and one at the bottom, with a shade in between and covering a window opening. Likewise, Dube, U.S. Pat. No. 4,865,107, discloses a pair of shade rollers located within a double glazed window assembly. Sullivan, U.S. Pat. No. 5,547,008, shows a system for opening and closing mini-blinds. Crider et al., U.S. Pat. Nos. 5,566,736, 5,752,557, 5,785,105 and 5,960,847, disclose a roll up closure that utilizes a flexible cover or curtain selected from a material suitable to affect the type closure sought such as against light, ventilation, noise, sound or moisture. The cover is at least as wide as the opening to be covered and is longer than the opening is high. Each lateral margin of the cover has a strip of closure material affixed thereto, and a complimentary strip is affixed to the inside of a channel member. The top of the curtain is rigidly affixed across the top of the opening. The bottom of the curtain is upturned and connected to a driven take up roller mounted atop the opening. An elongated rod is supported within the upturned end of the curtain with its ends captured within the channels on each side of the opening. A weighting rod is supported atop the elongated rod and separated therefrom by the upturned end of the curtain, with the ends of the weighting rod also captured in the lateral channels. Activation of the driven roller lengthens or shortens the effective length of the curtain and moves the rods upwardly within the channels such that the mating closures are positioned to seal and unseal the curtain to the channel.
Anderson et al., U.S. Pat. No. 7,281,561, discloses a window assembly containing multiple layers of flexible film used to effect various open to closed positions. In spite of all the above cited art, Applicants are not aware of a single prior art system that enables a user to regulate the amount of illumination and solar gain generated by a window opening, for example only, with the ability to completely to progressively darken and even “black out” the light entering through the opening with a shade. Further, Applicants are not aware of a prior art system that provides for the creation of multiple layers of shade material from a single length of shade and which provides for gradual adjustment of transmitted light from totally open to totally blacked out.
Thus, there is a need in the art for a system and method for providing an easy to use, easy to maintain room darkening screen for openings, such as for example only, windows. It, therefore, is an object of this invention to provide a room darkening screen for use with openings that allows a user to adjust from fully open to fully blacked out and in between. Further it is an object to provide a system that creates layers of screen or shades from a single length of shade and that is easily adjustable to accommodate openings of different lengths and widths.